Stoker and furnace therefor



g- 9 9- M. C; RICHARDSON 2,170,277

STOKER "AND FURNACE THEREFOR Filed Sept. 21, 1936 6 Sheets-Sheet 1 Ari-UN;

Aug. 22, 1939. M. c. RICHARDSON STOKER AND FURNACE THEREFOR 6Shets-Sheet a Filed Sept. 21, 1936 v/NA/ENTUR M.c.- R\CH/-\RDSON E Aug.22, 1939.

Filed Sept. 21, 1936 6 Sheets-Sheet -4 ::I 39 95 109 EI:: x ma A M 40 /337 3 112 g 5 7o 1 4 42 I u 4i 0/ 71 102 v 30 {as nvz/swraa M.CRICHAQDSON 9 M. c; RICHARDSON 2,170,277

STOKER AND FURNACE THEREFOR Filed Sept. 21, 1936 6 Sheets-Sheet 5 I M EY lNLf/VTUR MLRICHARDSOH B V W 22, 3 M. c. RICHARDSON 2,170,277

STOKER AND FURNACE THEREFOR Filed Sept. 21, 1936 6 Sheets-Sheet 6Patented Aug. 22, 1939 UNITED STATES PATENT' OFFICE I STOKER AND FURNACETHEREFOR Max 0. Richardson, Portland, Oreg., assignor to Iron FiremanManufacturing Company, Port- 7 land, Oreg.

Application September 21, 1936, Serial No. 101,800

6 Claims. (01. 110-45) This invention relates generally to heatingsysparts of relatively small dimensions may be emtems and particularlyto a combined form of ployed. stoker and boiler. The twelfth object isto provide a coal feeding The main object of this invention is toprovide worm adapted to extend through a stoker retort a completeheating system in which alarge part in which the helix of the wormopposes itself 5 of the stoking mechanism is incorporated in the underthe retort and in which the connection boiler itself. between theopposing worm parts serves as an The second object is to provide acombined agitator. boiler and stoker having a straight line arrange- Thethirteenth object is to provide an improved 1o ment for the coalconveyor between the coal storform of horizontal, tank type of hopper.age section and the coal burning section and a The fourteenth object isto develop a heating continuous conveyor from the coal burning secsystemin which there is a straight line progress tion to the ash dischargepoint. of coal from the bin'to the combustion section,

The third object is to construct a heating sysand upward progress of'coal into the combustion tom of the type described so the fly ash whichsection, then a straight forward progress of coal 15 may pass over intothe passages of the boiler will during combustion, and a dropping of therefuse fall into locations above and adjacent to the ash into the ashworm' on the same axis 'as the coal worm in a manner such that it may bereadily worm, and the collection of fly ash from the boiler dumped intothe ash worm without other manual and the depositing of same into theash -worm. 2o handling. I accomplish these and other objects in the Thefourth object is to provide an improved manner set forth in thespecification following form of burning grates adapted to be used in asillustrated in the accompanying drawings, in conjunction with thestoker. .which:

The fifth object is to use an exhaust fan ar- Fig. 1 is a perspectiveview showing the boiler rangement for drawing off. the' products ofcomand furnace portion in vertical section in which 25 bustion and touse a simple form of damper which the firepot isshown in elevation.

will permit the furnace to be automatically freed Fig. 2 is a sectiontaken along the line 2-2 in of explosive gases during the shutdownperiod Fig. 8. 1 and which will automatically cause the combus- Fig. 3is a section taken along the line3--3 in tion gases to travel the properheating path dur Fig. 2. 30 ing the operation of the stoker. Fig. 4 is asection taken along the line 4+4 in The sixth object is to arrange thecombined Fi 3.

boiler and stoker so an exhaust fan will draw oif Fig. 5 is a sectiontaken along the line 5-5 in the burned gases and that the fan may bemounted adjacent to a gear case and that both the fan Fi 6 is a a m yrear l vat n f th '35 and the worm driving gears may be driven from coaltank or hop Y a single motor. Fig. '7 is a vertical section taken alongthe line The seventh object is to use an improved form in of hollow orcareless worm, Fig. 8 is an enlarged vertical section taken The eighthobject is to construct thesystem 1ng itudi1}a]'1y tmfough the P 40 so itmay be used either in connection with a 9 1S a horizontal section takenalongfthe coal bin or a hopper. i I 1 The ninth object 1 1, so constructthe System Fig. 10 IS a broken vertical section taken along the linel0-l0 in Fig. 8.

that It can be used to an equal advantage with Fig. 11 is a verticalsection taken along the line 45 warm air furnaces as well as inconnection with in Fig 8 fg and F TP Fig. 12 isa fragmentary rearelevation of the he tenth obJect is to provide an improved systemshowing the fan i transmission cas- P system 9 the type descnbed Incolumn ing, the ashelevating conveyor, and the ash can non 71thspeclal'fonfl of ash removerbroken away in section to disclose theinterior 50 The eleventh ob ect is to construct'a stoker of thereof. eyp described wi w to keeping the Fig. 13 is an enlargedverticalsection-through i t thereof a a Inlnimllm and c mplishing thedrive mechanism of the coal and ash worm. this saving by starting fromthe basis of a small Fig. 14 is a horizontal section showing theemdlameter, hollow worm in conjunction with which ployment of an exhaustfan. I55

' extends the double top 23. The front 28 is pro.-

vided with a fire door opening 24 in front of which is placed a firedoor 25. The back 2I is provided with a smoke outlet opening 25A whichcommunicates by means of a smoke duct 26 with a stack not shown. Withinthe smoke duct 26 is placed a. hanging damper 21 which is adapted toclose when the furnace is operating and open under a negative pressureproduced by the stack when the stoker is not being operated for thepurpose of permitting the removal of gases from within the furnace. Thesmoke duct 26 communicates with a suction fan 28 whose intake 29 extendsthrough the back wall 2I and whose discharge 38 communicates by means ofthe duct 3I with the smoke duct 26.

Within the boiler is placed the transverse wall or water leg 32 throughwhose upper portion is formed the opening 33 which in this instanceregisters with the opening 25 of the back 2I. The walls 28, 2|, and 22and the wall 32 rest upon the rectangular base composed of the front 34,the back 35,'and sides 36. v Between the sides 36 and directlyunderneath the wall 32 is placed a wall 31. Between the wall 31 and theback 35 is formed a curved trough 38 in which is free to rotate thefluted ash gate 39 which is rotatably mounted on the shaft 48 whichjournals in the sides 36. The trough 38 is provided with an opening 4|along its lower side through which the blades 42 project. The front side43 of'the wall is mounted on one end 48 of a tank or hopper 58.Extending along the bottom of the tank 58 to the front side of theretort 44 is a worm A portion ofthe worm II which is within the tank 68is providedwith a core 52 on the front end of which is secured a crank53 whose hub 54 journals in the bearing 65 which forms a part of thetank 58.

Along the longitudinal axis of the tank 58 are placed the short shafts66 and 51 from the inner ends of which are suspended the forked arms 68on the lower ends of which are disposed the agitator shoes 59. A rockingmotion is imparted to the shaft 56 by means of the slotted arm 68 whichis attached to one of the shafts 66. The

in the bottom of the tank 58. The tank 58 issupported by means of thestandards 63.

The end 64 of the retort is cylindrical and coaxial with the coal tube41. The end 64 constitutes an ash removing duct and contains a wormflight 65 which is threaded oppositely to the worm 5I. The members 5|and 65 are joined by an agitator bar 66 which is inclined with relationt0 the axes of the members SI and 65. The hollow worm flight 65 isprovided with a spliced coupling 61, and its end 68 is secured to thecam shaft 69 which forms the core for the end of the ash removing wormIII. The ash removing worm I8 is disposed within the ash removing tubeII which extends into the end I2 on the wall I3 which connects the sidesI4. The sides 14 and the wall 13 extend from the floor plate I5 to theoutwardly flanged edges I6. Brackets TI project from the sides I4 andsupport the transverse bar I8. A central support 19 projects from thewall I3 above the connection I2. The side 88 of the retort 44 is slopingand its upper edge lies between the side walls I4.

Between the bar I8 and the edge 8| of the side 88 is disposed the uppersliding grate 82. Between the bar I8 and the support 19 is the lowersliding grate 83. are perforated and integral with the side members 84.

Projecting downwardly from the lower grate 83 are the lugs 85. Hinged tothe lugs 85 are the upright arms 86, which are joined by the slottedtransverse bar 81.. On the shaft 89 is disposed a cam 88, which engagesthe slot 89 in the bar '81. The lower ends of the arm 86 are providedwith slots 98 which receive 'the pins 9| which project outwardly fromthe adjacent faces of the lugs 92, which are integral with the wall I3.

The portion of the device just described constitutes the shaking grateby means of which ashes are carried away from the retort to the ash wormI8. It can be seen that a rotary motion imparted to the worms 5| and I8will cause the cam 88 to move the arms 86 and reciprocate the grates 82and 83, permitting the burning coal to spread over a relatively largegrate surface, upon which it may be burned before passing over the edge93 of the lowermost grate 83.

It will be noted that the upper side of the ash duct II is cut away fromthe connection I2 to the back 35 in order to permit the ashes which Thegrates 82 and 83' are discharged from the grate 83 to find their wayinto the ash duct 'II.

The fan 28 is operated by a motor 94 which rests upon a shelf 95 formedat the upper end of the upright standard 96 through which the ash duct'II projects. The ash duct 'II communicates with an ash conveyor housing91 which is preferably inclined and discharges downwardly into the ashcan 98 through a convenient connection 98.

The ash removing worm III has secured to the driven end thereof a shaftI88 on which is placed a sprocket wheel I8I, which carries the chain I82whose flights I83 travel around the interior of the housing 81 and serveto elevate the ashes from the bottom of the housing 91 and dischargethem through the connection 99.

The shaft I88 is provided with a short section of worm flight I84 whichis reversed with rela-' tion to the worm 18 in order to prevent ashesfrom passing axially beyond the conveyor housing 91. The shaft I88 isjoined by the universal joint I85 to the shaft I86 of the worm wheelI81,

which is driven by the worm I08 on the shaft I09. The shaft I69 isdriven through the helical gears III! and III, the latter of which issecured on the shaft II2, on the outer end of which is secured a pulleyII3 whose belt II4 passes around the pulley I I5 of the motor 94. Theshaft I66 is provided with a thrust bearing II6 which permits the entireworm sections to be operated in tension, Obviously, the details ofconstruction may be modified greatly without departing from the spiritof this invention.

It will be noted that the blades 42 engage the flights of the worm III,the purpose being to cause the rotation of the worm III to produce arotation of the ash gate 39.

In this form of the system, it is contemplated to rely upon amechanically created negative pressure being formed within thecombustion chamber 1. v

Air is admitted to the combustion chamber I I1 through an air duct H8,which connects the plenum chamber II 9 formed around the retort 44 andthe atmosphere under the control of the damper I20. Air is drawn throughthe air duct I I8 and delivered to the burning fuel through the openingsI2I, I22, and I23 and between the grates 82 and 83 and their adjacentmembers BI, I8, and 19. The gaseous products of combustion are drawnthrough the opening 33 and thence carried downwardly through thepassageway I24 through the fan inlet 29 into the fan 28 from whence theyare discharged through the duct 3| into the smoke duct 26. Obviously,such an action produces a higher pressure Within the duct 26 than existswithin the combustion chamber I I1, thereby causing the damper 21 toclose.

It will be observed that during the downward travel'of the burned gasesthrough the passageway I24, the solids will be inclined to pass the fanopening 29 and be deposited between the blades 42 of the ash gate 39 andthence be discharged into the ash removing worm l0. Ashes may enter theash worm I directly from the lower grate 83 while fly ash may enter theworm III by passing around the ash gate 39.

When the motor 94 is not operating, that is, when the fan 28and theworms and III are not being operated, a reverse condition exists, andthere is a negative pressure within the smoke duct 26 which causes thedamper 21 to open, and gases which may have formed within the combustionchamber III are allowed to pass through the openings 33 and 25 and toescape through the smoke pipe 26 to the atmosphere.

In Fig. 11 is shown the preferred type of coupling for the sections ofthe worm flight 65. It will be noted that this construction facilitatesthe joining of the worm parts and permits the separation of the entireworm assembly into lengths convenient for handling.

In the form of the device shown in Figs. 15 to 1'7 inclusive, theconstruction is the same as in the first described form of the deviceexcept in the following particulars. An additional bafiie I25 isinterposed between the back 2IA and the transverse baflie 32A, thebaffle I25 being directly above the ash gate 39. Instead of employing anexhaust fan in this form of the device, I use a pressure fan I26 whichdelivers air through the air duct I21 to the plenum chamber II9. It isalso desirable in this form of the construction to employ an airregulating damper I28 within the duct I21. When a pressure fan isemployed, it is desirable to provide an auxiliary air line I 29, whichestablishes communication between the fan I26 and the coal tube 41.

In the last described form of the device, the automatic damper I30 maybe placed at the top of the baflle I25 instead of in the smoke pipe I3I.The remaining parts are substantially the same as in the first describedform of the device.

I claim:

1. In a device of the class described, the combination of a furnacehaving a bridge wall across one end thereof adapted to form a combustionchamber on one side of said bridge wall and a down draft passage on theother side of said bridge wall, said wall extending upwardly andterminating near the upper part of the furnace, an ash gate forming aclosure for the bottom end of said down draft passage, said gateconsisting of a revolvable fluted member, a retort at the end of saidcombustion chamber opposite said bridge wall, stepped shaker gratesbetween said retort and bridge wall, a duct extending through saidfurnace and retort and below said grates and ash gate, said duct beingcut away on its top side to admit ashes thereto, a revolvable conveyingelement within said duct consisting of a coal conveying screw flightextending from one end of said duct to the near side of said retort, anash removing flight extending from under said grates to an ash outlet, areversed flight secured between said coal and ash flights, the junctionof said coal and reverse flights being at the bottomof the retort andconsisting of a diagonal bar connecting the adjacent ends of thereversely wound flights, a lever hinged at one end to a support and atthe other end to the shaker grates and a cam on the axis of saidconveyor for actuating said lever in a manner to reciprocate said gratesas the conveyor is turned.

2. The combination of a retort having a coal conveyor worm associatedtherewith with means for feeding fuel upwardly into said retort, gratesfor carrying the incombustibles away from the end of said retort and anash conveying worm forming a continuation of the coal conveyor forcarrying ashes away from the end of said grates.

3. In a furnace the combination of a combustion chamber having avertical bridge wall disposed transversely across one end thereof toform a down draft passage between said bridge wall and one adjacent endof the combustion chamber, said combustion chamber being provided withash'outlets in front of and behind said bridge wall, a closure for theash outlet of said down draft passage, a retort in the bottom of saidcombustion chamber including moving grates for discharging ashes throughthe outlet in front of said bridge wall, a worm conveyor extendingthrough said retort and having one end projecting into a coal containerto draw coal therefrom and having the other end extending past said ashoutlets to carry ashes therefrom, a can for drawing gaseous products ofcombustion from said down draft passage and a damper for permitting thegaseous products of combustion to be drawn off over said bridge wall bynatural draft when said fan is not being operated.

4. The combination of a retort, a conveying worm extendingthere'through, one end of said Worm constituting a coal conveyor fordrawing coal into said retort and the other end of said wormconstituting an ash conveyor for removing ashes from said retort, ashaker grate along one end of said retort over which ashes can pass intosaid ash conveying worm, a cam mounted on said ash conveying worm and alever actuated by said cam and connected to said grates whereby therotation of said ash conveying worm will produce a reciprocating motionat said grates.

5. The combination with a combustion chamber of a retort, a conveyingworm extending therethrough, one end of said worm constituting a coalconveyor for drawing coal into said retort and the other end of saidwormconstituting an ash conveyor for removing ashes from said retort, a

shaker grate along one end of said retort over which ashes can pass intosaid ash conveying worm, a cam mounted on said ash conveying worm, alever actuated by said cam and connected to said grate whereby therotation of said ash worm will produce a reciprocating motion at saidgrates, and a transverse bridge wall extendashes can pass from behindsaid bridge wall into said ash worm. r

6. The combination of a retort, a worm extending therethrough, one endof said worm being adapted to draw coal from a storage point to said 1retort and the other end or said worm constituting an ash conveyor forremoving ashes from said retort, a shaker grate at one end of saidretort over said ash removing worm and means for actuating said shakergrate from said ash 15 worm.

MAX C, RICHARDSON.

